Interpretive Summary: Ability to boost immune response to simple proteins of enteric bacteria is needed to develop an effective recombinant vaccination strategy against some pathogens which are difficult to control using conventional live vaccines. ARS scientists collaborated with scientists from Korea and France to show that a commercially available mineral oil-in-water adjuvant elicited host immune response to protein antigens when protein antigens were emulsified in this adjuvant. The commercial Montanide™ ISA 71 VG adjuvants elicited serum antibodies against clostridium proteins that were used as immunogens and induced partial protective immune response when vaccinated birds were challenged with live Clostridium perfringens. Based on immunological parameters that were evaluated in this study, this commercial ISA 71 VG mineral oil-in-water adjuvant showed immune enhancing effect in broiler chickens. These results suggest that vaccination with certain clostridial proteins in combination with ISA 71 VG mineral oil adjuvant enhances mucosal immunity against experimental necrotic enteritis in broiler chickens.